In my opinion, here are the guys the Sioux have the best chance at from the list above:
Mario Lamoreaux will probably end up with the Sioux. He's keeping his options open right now, but Brent Sutter gave him a pretty solid pitch this fall to come to the WHL and he didn't go. That could change this summer if he decides he doesn't want to play in the USHL again next year, but otherwise, I'm pretty confident he'll up with the Sioux.
I like their chances with Aaron Marvin, Derrick Lapoint, and Ben Winnett too. If I had to guess, I'd say all three of those guys will end up with the Sioux. They're probably at least interested in the other guys as well. One name that isn't on that list that probably should be is Colton Grant from Alberta. He'll be very highly recruited by a lot of WCHA teams.
You can probably cross Alex Kangas off the list. He doesn't want to wait until 2007, and if for whatever reason, he did wait, he'd likely end up with the Gophers.
I should add that they probably have good chances at some of the 2008 guys, but it's way too early to tell how good those chances are.